Reload shaft assembly for surgical stapler

ABSTRACT

A surgical stapling system can include a reload shaft. The shaft can include an elongate tubular member with have a jaw assembly at the distal end thereof and a coupling collar at the proximal end thereof. The shaft assembly also includes an articulation joint coupling the jaw assembly to the distal end. A drive member and an articulation member extend within the tubular body of the shaft from the proximal end to the distal end. A firing member is connected to the distal end of the drive member such that advancement of the drive beam advances the firing member to close the jaw assemblies and fire staples from a reload positioned in the jaw assembly. The shaft assembly can also include a lockout mechanism to prevent a firing operation on a previously-fired reload or no reload.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of U.S. patent application Ser. No.15/486,227, entitled “RELOAD SHAFT ASSEMBLY FOR SURGICAL STAPLER,” filedApr. 12, 2017, currently pending, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/321,618, entitled “RELOADSHAFT ASSEMBLY FOR SURGICAL STAPLER,” filed Apr. 12, 2016. Theabove-referenced applications are each incorporated by reference hereinin their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

The present application relates generally to surgical occlusioninstruments and, more particularly, to surgical staplers.

Description of the Related Art

Surgical staplers are used to approximate or clamp tissue and to staplethe clamped tissue together. As such, surgical staplers have mechanismsto ensure that tissue is properly positioned and captured and to drivestaples through the tissue. As a result, this has produced, for example,multiple triggers and handles in conjunction with complex mechanisms toprovide proper stapling of the clamped tissue. With these complexmechanisms, surgical staplers can have increased manufacturing burdens,as well as potential sources for device failure and confusion for theuser. Thus, reliable stapling of clamped tissue without complexmechanisms is desired.

SUMMARY OF THE INVENTION

In certain embodiments, a surgical stapler is provided herein. Thesurgical stapler comprises an elongate shaft, a jaw assembly, and ahandle assembly. The elongate shaft has a proximal end and a distal end.The elongate shaft defines a longitudinal axis between the proximal endand the distal end. The jaw assembly is positioned at the distal end ofthe elongate shaft. The jaw assembly comprises a first jaw, a secondjaw, and a plurality of staples. The jaw assembly is selectivelypositionable in one of a closed configuration, an open configuration,and a firing configuration. The handle assembly is positioned at theproximal end of the elongate shaft.

In certain embodiments, the elongate shaft comprises a jaw assembly atthe distal end thereof coupled at an articulation joint. Thearticulation joint can allow articulation of the jaw assembly about anarticulation range. Translation of an articulation member that extendsthrough the elongate shaft articulates the jaw assembly. The elongateshaft further comprises a drive member extending through the elongateshaft. The drive member has a flexible segment extending through thearticulation joint. A firing member is coupled to the distal end of thedrive member.

In certain embodiments, the jaw assembly at the distal end of theelongate shaft comprises a reload support and an anvil pivotably coupledto the reload support. A firing member having an I-beam configuration ispositioned in the jaw assembly. The jaw assembly can further comprise alockout mechanism to prevent the firing member from being advancedunless an unfired reload is positioned in the jaw assembly.

In various embodiments, a shaft coupler can be positioned at theproximal end of the shaft. The shaft coupler can be configured to engagea coupler on a handle assembly in a bayonet connection. The bayonetconnection simultaneously couples an articulation member, a drivemember, and the elongate shaft. The coupler can further comprise a shaftidentification mechanism. The coupler can further comprise a lock-inmechanism to retain the shaft assembly in connection with the handleassembly.

In various embodiments, a reload assembly for a surgical stapling systemis provided. The reload assembly comprises an elongate shaft, a jawassembly, a firing member, an actuation beam, and a reload lockoutmechanism. The elongate shaft has a proximal end and a distal end. Theelongate shaft defines a longitudinal axis extending between theproximal end and the distal end. The jaw assembly is positioned at thedistal end of the elongate shaft. The jaw assembly comprises a firstjaw, and a second jaw. The first jaw comprises a reload supportconfigured to receive a staple reload. The second jaw is pivotablycoupled to the first jaw. The second jaw comprises an anvil surface. Thefiring member is longitudinally slidable within the jaw assembly. Theactuation beam is longitudinally slidable within the elongate shaft. Theactuation beam has a proximal end and a distal end. The distal end ofthe actuation beam is coupled to the firing member. The reload lockoutmechanism comprises a lockout lever pivotally coupled to the reloadsupport and pivotable between a locked position preventing distalmovement of the actuation beam relative to the elongate shaft and anunlocked position allowing distal movement of the actuation beamrelative to the elongate shaft.

In various embodiments, a reload assembly for a surgical stapling systemis provided. The reload assembly comprises an elongate shaft, a jawassembly, an actuation beam, and a shaft coupler. The elongate shaft hasa proximal end and a distal end and defines a longitudinal axisextending between the proximal end and the distal end. The jaw assemblyis positioned at the distal end of the elongate shaft. The jaw assemblycomprises a first jaw, and a second jaw. The first jaw comprises areload support configured to receive a staple reload. The second jaw ispivotably coupled to the first jaw. The second jaw comprises an anvilsurface. The actuation beam is longitudinally slidable within theelongate shaft. The actuation beam has a proximal end and a distal end.The distal end of the actuation beam is coupled to the jaw assembly. Theshaft coupler is positioned at the proximal end of the elongate shaft.The shaft coupler comprises a locking member positioned therein. Thelocking member is radially outwardly advanceable by distal actuation ofthe proximal end of the actuation beam.

In various embodiments, a reload assembly for a surgical stapling systemis provided. The reload assembly comprises an elongate shaft, a jawassembly, an actuation beam, and a shaft coupler. The elongate shaft hasa proximal end and a distal end and defines a longitudinal axisextending between the proximal end and the distal end. The jaw assemblyis positioned at the distal end of the elongate shaft. The jaw assemblycomprises a first jaw and a second jaw. The first jaw comprises a reloadsupport configured to receive a staple reload. The second jaw ispivotably coupled to the first jaw. The second jaw comprises an anvilsurface. The actuation beam is longitudinally slidable within theelongate shaft. The actuation beam has a proximal end and a distal end.The distal end of the actuation beam is coupled to the jaw assembly. Theshaft coupler is positioned at the proximal end of the elongate shaft.The shaft coupler is configured to removably couple to a handleassembly. The shaft coupler comprises a lockout mechanism positionedtherein. The lockout mechanism comprises a locking ring and a lockoutmember. The locking ring is rotatable about the longitudinal axis. Thelockout member is radially outwardly advanceable by rotation of thelocking ring.

In various embodiments, a reload assembly for a surgical stapling systemis provided. The reload assembly comprises an elongate shaft, a jawassembly, an actuation beam, an articulation link, a support link, andan articulation latching mechanism. The elongate shaft has a proximalend and a distal end and defines a longitudinal axis extending betweenthe proximal end and the distal end. The jaw assembly is articulablycoupled to the elongate shaft at the distal end of the elongate shaft.The jaw assembly comprises a first jaw and a second jaw. The first jawcomprises a reload support configured to receive a staple reload. Thesecond jaw is pivotably coupled to the first jaw. The second jawcomprises an anvil surface. The actuation beam is longitudinallyslidable within the elongate shaft to actuate the jaw assembly. Theactuation beam has a proximal end and a distal end. The articulationlink is longitudinally slidable within the elongate shaft to articulatethe jaw assembly relative to the elongate shaft. The articulation linkhas a proximal end positioned adjacent the proximal end of the elongateshaft and a distal end pivotably coupled to the jaw assembly. Thesupport link is longitudinally slidable within the elongate shaft. Thesupport link has a proximal end extending longitudinally to a distal endpivotably coupled to the jaw assembly. The articulation latchingmechanism is positioned within the elongate shaft between the proximalend and the distal end. The articulation latching mechanism has anunlatched configuration in which the articulation link and the supportlink are slidable within the elongate shaft and a latched configurationwherein the articulation latching mechanism engages the articulationlink and the support link to prevent longitudinal sliding of thearticulation link and the support link.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of surgical staplingsystem with the jaws in an open configuration;

FIG. 2a is a perspective view of several embodiments of shaft assemblyfor the surgical stapling system of FIG. 1;

FIG. 2b is a perspective view of several embodiments of jaw assembly forthe surgical stapling system of FIG. 1;

FIG. 3 is a perspective view of a jaw assembly at the distal end of theshaft assembly for the surgical stapling system of FIG. 1;

FIG. 4 is a perspective view of the jaw assembly of FIG. 3 with a staplereload;

FIG. 5 is a perspective view of the jaw assembly of FIG. 3 with a staplereload inserted;

FIG. 6A is a top view of an anvil for the jaw assembly of FIG. 3;

FIG. 6B is a top view of an anvil plate for the jaw assembly of FIG. 3;

FIG. 7 is an exploded perspective view of the anvil of the jaw assemblyof FIG. 3;

FIG. 8 is a perspective view of the top jaw of the jaw assembly of FIG.3 in an initial state and a formed state;

FIG. 9 is a perspective view of the anvil surface of the jaw assembly ofFIG. 3;

FIG. 10 schematic diagram of staple recesses in the anvil surface ofFIG. 9;

FIG. 11A is a perspective view of the anvil of the jaw assembly of FIG.3;

FIG. 11B is a top view of the anvil of the jaw assembly of FIG. 3;

FIG. 12 is a perspective view of the reload support of the jaw assemblyof FIG. 3 with a reload partially inserted;

FIG. 13 is a perspective view of the reload support of the jaw assemblyof FIG. 3 with a reload inserted;

FIG. 14 is a side view of a closure beam of the jaw assembly of FIG. 3;

FIG. 15 is a partial cut-away front view of the closure beam of FIG. 14with a flange thereof positioned in a channel in the anvil of the jawassembly of FIG. 3;

FIG. 16 is an exploded perspective view of a reload for use in thestaple system of FIG. 1;

FIG. 17 is an upper perspective view of the reload for use in the staplesystem of FIG. 1;

FIG. 18 is a lower perspective view of the reload for use in the staplesystem of FIG. 1;

FIG. 19 is an exploded lower perspective view of the reload for use inthe staple system of FIG. 1;

FIG. 20 is a perspective view of the reload for use in the staple systemof FIG. 1;

FIG. 21 is a top detail view of the reload for use in the staple systemof FIG. 1;

FIG. 22 is a perspective view of a staple pusher for the reload of FIG.16;

FIG. 23 is a perspective view of a staple pusher of the reload of FIG.16;

FIG. 24 is a perspective view of the reload for use in the staple systemof FIG. 1;

FIG. 25 is a partial cut-away view of the jaw assembly of FIG. 3 in aclosed configuration;

FIG. 26 is a perspective view of the reload of FIG. 16;

FIG. 27 is a perspective view of the jaw assembly of FIG. 3 in a closedconfiguration with a reload inserted;

FIG. 28 is a perspective view of the jaw assembly of FIG. 3 with areload positioned for insertion;

FIG. 29 is a perspective view of the jaw assembly of FIG. 3 with areload inserted;

FIG. 30 is a top view of the reload of FIG. 16;

FIG. 31 is a side view of the jaw assembly of FIG. 3 with a reloadinserted;

FIG. 32A is a perspective view of a reload lockout mechanism of theshaft assembly;

FIG. 32B is a side view of the reload lockout mechanism of the shaftassembly;

FIG. 33 is a side view of the reload lockout mechanism of the shaftassembly in a locked configuration;

FIG. 34 is a side view of the reload lockout mechanism of the shaftassembly in an unlocked configuration;

FIG. 35 is a perspective view of the distal end of the elongate shaft atan articulation joint connection with the jaw assembly of FIG. 3;

FIG. 36 is a partial cut-away perspective view of one embodiment ofarticulation joint at the distal end of the elongate shaft;

FIG. 37 is a partial cut-away perspective view of one embodiment ofarticulation joint at the distal end of the elongate shaft;

FIG. 38A is a partial cut-away top view of the articulation joint ofFIG. 36 in an articulated position;

FIG. 38B is a partial cut-away top view of the articulation joint ofFIG. 36 in another articulated position;

FIG. 39 is a partial cut-away perspective view of another embodiment ofarticulation joint at the distal end of the elongate shaft;

FIG. 40 is a partial cut-away perspective view of the embodiment ofarticulation joint of FIG. 39 at the distal end of the elongate shaft;

FIG. 41 is a partial cut-away top view of the articulation joint of FIG.39 in an articulated position;

FIG. 42 is a partial cut-away top view of the articulation joint of FIG.39 in another articulated position;

FIG. 43 is a partial cut-away top view of the articulation joint of FIG.39 in a latched position;

FIG. 44 is a side view of the proximal end of the shaft assemblypositioned adjacent a handle assembly for the stapler system of FIG. 1;

FIGS. 45A-45D are perspective views of a coupling of the proximal end ofthe shaft assembly to the handle assembly in a stapler system of FIG. 1;

FIG. 46 is an exploded perspective view of the proximal end of the shaftassembly of the stapler system of FIG. 1;

FIG. 47 is a cut-away side view of the proximal end of the shaftassembly positioned adjacent a handle assembly for the stapler system ofFIG. 1;

FIGS. 48A-48B are perspective views of a coupling of the proximal end ofthe shaft assembly to the handle assembly in a stapler system of FIG. 1;

FIGS. 49A-49B are perspective partial cut-away views of a coupling ofthe proximal end of the shaft assembly to the handle assembly in astapler system of FIG. 1;

FIG. 50 is a perspective partial cut-away view of the proximal end ofthe shaft assembly in a stapler system of FIG. 1;

FIG. 51 is a perspective partial cut-away view of the proximal end ofthe shaft assembly in a stapler system of FIG. 1; and

FIG. 52 is an exploded perspective view of the proximal end of the shaftassembly in a stapler system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, an embodiment of surgical stapling system isillustrated. The illustrated embodiment of surgical stapler 10 comprisesan elongate shaft 20, a jaw assembly 30, and a handle assembly 40. FIG.1 illustrates the surgical stapler 10 with the jaw assembly 30 in anopen configuration. A staple reload 50 can be positioned in the jawassembly. While the illustrated surgical stapling system is illustratedwith a powered handle, it is contemplated that the elongate shaft 20 andjaw assembly 30 can be interchangeably used in a stapling systemincluding a mechanical stapler handle. For example, it is contemplatedthat the various embodiments of elongate shaft assembly 20 and jawassembly 20 described herein can be used interchangeably with either thepowered handle assemblies described in U.S. patent application Ser. No.15/486,008, entitled “SURGICAL STAPLER HAVING A POWERED HANDLE,” filedApr. 12, 2017, currently pending, and the mechanical manually actuatedhandle assemblies described in U.S. patent application Ser. No.15/485,620, entitled “SURGICAL STAPLER HAVING ARTICULATION MECHANISM,”filed Apr. 12, 2017, currently pending. These applications areincorporated by reference herein in their entireties.

With continued reference to FIG. 1, the illustrated embodiment ofsurgical stapler 10 can be sized and configured for use in laparoscopicsurgical procedures. For example, the elongate shaft 20 and jaw assembly30 can be sized and configured to be introduced into a surgical fieldthrough an access port or trocar cannula. In some embodiments, theelongate shaft 20 and jaw assembly 30 can be sized and configured to beinserted through a trocar cannula having a relatively small workingchannel diameter, such as, for example, less than 8 mm. In otherembodiments, elongate shaft 20 and jaw assembly 30 can be sized andconfigured to be inserted through a trocar cannula having a largerworking channel diameter, such as, for example, 10 mm, 11 mm, 12 mm, or15 mm. In other embodiments, it is contemplated that certain aspects ofthe surgical staplers described herein can be incorporated into asurgical stapling device for use in open surgical procedures.

With continued reference to FIG. 1, as illustrated, the elongate shaft20 comprises a generally tubular member. The elongate shaft 20 extendsfrom a proximal end to a distal end. The elongate shaft 20 defines acentral longitudinal axis, L. of the surgical stapler 10 extendingbetween the proximal end and the distal end.

With reference to FIG. 2a , it is contemplated that the stapling systemcan include an elongate shaft having a desired length. While thefeatures of the jaw assembly and handle coupling described herein can besubstantially similar for each of these shaft assemblies, the shaftbodies can be scalable. For example, a stapling system can include arelatively short elongate shaft 20′, a mid-length elongate shaft 20, ora relatively long elongate shaft 20″. Each of these shaft lengths canhave particular applicability for a subset of patients or procedures.For example, the short elongate shaft 20′ can be useful in pediatricprocedures, and the long elongate shaft 20″ can be useful in bariatricprocedures.

With reference to FIG. 2b , it is contemplated that the stapling systemcan include a jaw assembly having a desired length. While the featuresof the jaw assembly and articulation joint described herein can besubstantially similar for each of these shaft assemblies, the jawassemblies bodies can be scalable. For example, a stapling system caninclude a relatively short jaw assembly 30′, a mid-length jaw assembly30, or a relatively long jaw assembly 30″. Each of these jaw assembliescan have particular applicability for a subset of patients orprocedures. In certain embodiments, it is contemplated that the jawassembly have a length of approximately 45 mm. In other embodiments, itis contemplated that the jaw assembly have a length of approximately 60mm.

With continued reference to FIG. 1, in the illustrated embodiment, thejaw assembly 30 is coupled to the elongate shaft 20 at the distal end 24of the elongate shaft 20. The jaw assembly 30 comprises a first jaw 32and a second jaw 34 pivotally coupled to the first jaw 32. In theillustrated embodiment, the jaw assembly 30 is articulable with respectto the elongate shaft 20.

With continued reference to FIG. 1, in the illustrated embodiment, thejaw assembly 30 can be actuated from an open configuration (FIG. 1) to aclosed configuration to a stapling configuration by an actuation memberor beam that is longitudinally slidable within the elongate shaft. In aninitial position, the beam can be positioned at the distal end of theelongate shaft 20. With the beam in the initial position, the second jaw34 is pivoted away from the first jaw 32 such that the jaw assembly 30is in the open configuration. The actuation beam engages the second jaw34 upon translation of the actuation member or beam distally along thelongitudinal axis L. Translation of the actuation beam distally from theinitial position a first distance can actuate the jaw assembly from theopen configuration to the closed configuration. With the jaw assembly 30in the closed configuration, the actuation beam can be returnedproximally the first distance to return the jaw assembly 30 to the openconfiguration. A distal end of the actuation beam can advance a stapleslider configured to deploy staples from the first jaw 32 such thatfurther translation of the actuation beam distally past the firstdistance deploys the plurality of staples from the reload positioned inthe first jaw 32.

With continued reference to FIG. 1, in the illustrated embodiment, thehandle assembly is coupled to the elongate shaft 20 at the proximal endof the elongate shaft 20. As illustrated, the handle assembly 40 has apistol grip configuration with a housing defining a stationary handle 42and a movable handle 44 or trigger pivotably coupled to the stationaryhandle 42. It is contemplated that in other embodiments, surgicalstapler devices including aspects described herein can have handleassemblies with other configuration such as, for example, scissors-gripconfigurations, or in-line configurations. As further described ingreater detail below, the handle assembly 40 houses an actuationmechanism configured to selectively advance an actuation shaftresponsive to movement of the movable handle 44.

With reference to FIG. 3, an embodiment of jaw assembly at the distalend of the shaft assembly 20 is illustrated. In the illustratedembodiment, the jaw assembly comprises a reload support 210 articulablycoupled to the distal end of the shaft assembly 20 at an articulationjoint 230. An anvil 220 is pivotably coupled to the reload support 210and defines a top jaw of the jaw assembly 30. A firing member 240 canslide within the jaw assembly to initially close the anvil 220 relativeto the reload support 210, then fire staples from a reload. In someembodiments, the firing member 240 has an I-beam configuration with avertical beam 242 spanning between two horizontally-protruding flanges244, 246. Advantageously, with an I-beam configuration, one horizontalflange 244 can engage a channel in the anvil 220 and the other flange246 can engage a channel in the reload or reload support to close thejaw assembly then maintain a desired closed spacing of the jaw assemblywhen the firing member is advanced distally. In some embodiments, thefiring member 240 can comprise a cutting blade 248 formed on or mountedto the vertical beam in an I-beam configuration. This cutting blade canseparate tissue as staples are fired to form staple lines on both sidesof the separated tissue.

With reference to FIGS. 4 and 5, the reload support 210 can be sized toreceive and retain a disposable reload 50. The reload 50 can be loweredand moved proximally into the reload support 210 until mating featureson the reload engage corresponding features on the reload support 210.

With reference to FIGS. 6A, 6B, 7, and 8, various aspects of the anvil220 of the jaw assembly 30 are illustrated. In certain embodiments, theanvil 220 comprises an anvil plate 222 coupled to a top surface 224. Theanvil plate can comprise a longitudinal channel 225 formed therein inwhich a horizontal flange of the firing member rides and a longitudinalslot 227 formed through the longitudinal channel 225 in which thevertical beam of the firing member rides. The top surface 224 can beformed of a sheet of material that is subsequently formed to overly theanvil plate. (FIG. 8 illustrates the flat sheet 224′ and shaped topsurface 224). Advantageously, the addition of the top surface 224 to theanvil plate 222 enhances the strength of the anvil of the jaw assembly.

With reference to FIGS. 9 and 10, various aspects of the anvil plate 222of the jaw assembly 30 are illustrated. The anvil plate comprises aplurality of staple forming pockets 223 thereon. In the illustratedembodiment, the staple forming pockets 223 are positioned in two arraysof three rows with the arrays positioned on either side of the slot forthe firing member. Thus, the stapler can form two sets of three linearrows of staples with the sets separated by divided tissue. In otherembodiments, it is contemplated that the anvil can include stapleforming pockets configured to form other numbers and configurations ofstaples. The staple forming pockets have a tapered configuration with arelatively large staple entry side narrowing to a relatively smallstaple formation side. Advantageously, this tapered configuration canguide staples to complete formation and reduce the incidence of poorlyformed staples. Adjacent rows of staples can be longitudinally offsetfrom one another such that the relatively wide entry sides of all of therows are offset from one another to reduce the overall width of the setsof staple rows.

With reference to FIGS. 11a and 11b , in certain embodiments of anvil220, the top surface 224 can be coupled to the anvil plate 222 by awelding operation along a weld line 226. Advantageously, this closedanvil formed by the welding operation covers the channel for the firingmember.

With reference to FIGS. 12 and 13, insertion of a reload 50 in thereload support 210 is illustrated. The reload support can compriseproximal jaw tabs 212 that protrude radially inwardly from side walls ofthe reload support 210 adjacent the proximal end thereof. The reload cancomprise a relatively short, tapered proximal deck 510 sized to bepositioned under and retained by the proximal jaw tabs. Moreover, thereload 50 can include retention tabs 512 protruding laterally outwardlyadjacent a distal end thereof. The reload support 210 can comprise acorresponding pair of retention recesses 214 sized and configured toreceive the retention tabs when the reload is positioned in the reloadsupport.

With reference to FIGS. 14 and 15, an embodiment of firing member 240having an I-beam configuration is illustrated. In the illustratedembodiment, The firing member comprises a vertical beam 242 having acutting blade formed therein at a leading edge. The cutting bladecomprises a curved cutting blade 248. A trailing edge of the firingmember 240 comprises a drive member interface 245 such as a cutout orprotrusion to allow the firing member to be securely coupled with thedrive member extending through the elongate shaft. The trailing edge ofthe firing member 240 can further comprise a lockout interface 247, suchas a proximally extending ‘tail’ that can position a reload lockout inan unlocked configuration when the firing member is in a proximalposition. The firing member further comprises an upper horizontal flange244 configured to ride in the channel 225 of the anvil and a lowerhorizontal flange 246 configured to engage the reload or reload support.As illustrated in FIG. 15, although the firing member has a generalI-beam configuration, in some embodiments the horizontal flanges arecurved or tapered such to conform with a shape of the channel 225 in theanvil. In some embodiments, the firing member 240 can further beconfigured to reduce friction during a firing sequence such as bysurface finishing operations, addition of a film lubricant, ordeposition of a low-friction surface on the firing member, channel, orboth.

With reference to FIGS. 16-19, an embodiment of reload 50 for use in thestapling system is illustrated. The reload 50 comprises a plurality ofstaples 520 positioned in a corresponding plurality of staple pockets532 formed in a cartridge 530. The staple pockets 532 are arranged intwo sets of three rows each with each set separated by a slot formedthrough the cartridge 530. The staples 520 rest in a plurality of staplepushers 540 underlying the staple pockets 532. A slider 550 having aramp 552 corresponding to each row of staple pusher 540 and a lockouttail 554 is positioned at the proximal end of the reload. The slider 550is longitudinally slidable within the reload responsive to movement ofthe firing member. A jacket 560 underlies the cartridge and maintainsthe staples and staple pushers in the staple pockets. The jacket canhave protruding hooks 562 to engage the cartridge.

With reference to FIG. 20, in some embodiments, the reload 50 caninclude a shipping cover 570 covering an upper surface of the cartridge.Advantageously, the shipping cover 570 can prevent one or more of thestaples from becoming dislodged from or misaligned within the staplepockets before the reload is used. The shipping cover 570 is removedbefore the reload 50 is positioned in the reload support.

With reference to FIGS. 21-23, in some embodiments, the reload 50 caninclude certain staple alignment and retention features. For example thestaple pockets 532 formed in the cartridge 530 can include staple guides534 at ends thereof to receive legs of the staples 520 positionedtherein. The staple pushers 540 can additionally include nubs 542 sizedand configured to ride in the staple guides 534. As illustrated, incertain embodiments, the staple pushers 540 can be formed in groups ofthree such that one staple pusher 540 can push a single staple in eachof three adjacent rows of staples. Moreover, an upper surface 544 ofeach of the staple pushers 540 can include a staple saddle configurationto relatively securely receive a staple. Secure positioning of thestaples 520 in the staple pushers 540 and engagement of the staple legsand nubs 542 of the staple pushers with the staple guides canadvantageously reduce the incidence of misaligned or malformed staples.

With reference to FIGS. 24-31, in various embodiments, the reload 50 andjaw assembly can be configured to be securely coupled to one another toalign the staple pockets on the reload 50 with the staple formingpockets on the anvil and maintain the position of the reload 50 in thejaw assembly during staple firing. The reload 50 can include upwardlyprotruding bosses 538 at a proximal end thereof (FIG. 24) that define atissue gap between the anvil 220 and an upper surface of the cartridge530 of the reload 50 with the jaw assembly in a closed configuration(FIG. 25). Moreover, the retention tabs 512 formed adjacent the distalend of the reload (FIG. 26) are positioned within recesses 214 of thereload support 210 and prevent the reload from shifting distally duringa firing operation. Thus, the reload 50 can be rapidly and securelycoupled to the reload support 210 (FIGS. 28-29). Additionally, aproximal end of the cartridge 530 can taper to a reduced height tofurther facilitate placement on the reload support (FIG. 30).Furthermore, the cartridge can be configured with a lowered distal end514 having a profile protruding below the reload support (FIG. 31). Thislowered profile ensures secure engagement of the reload with the reloadsupport.

With reference to FIGS. 32A, 32B, and 33-34, in certain embodiments, thejaw assembly can comprise a reload lockout mechanism 580. The reloadlockout mechanism 580 can prevent advancement of the firing member if noreload is positioned within the jaw assembly or if an empty reload ispositioned within the jaw assembly. The reload lockout mechanism 580includes a lockout lever 582 pivotally coupled to the reload support. Anaxis defined by the pivot extends generally transverse to thelongitudinal axis of the elongate shaft. With the firing member 240fully retracted such that the jaw assembly is in an open configuration,a tail 247 extending proximally from the firing member 240 maintains thelockout lever 582 pivoted to the unlocked position. In the illustratedembodiment, a proximal portion of the lockout lever 582 proximal thepivot is forked or bifurcated to receive the firing member 240 thereinsuch that the tail 247 can act on a surface of the lockout lever 582distal the pivot. If no reload is inserted, an attempt to advance thefiring member 240 will allow the lockout lever to pivot about a pivotpoint 584 from the unlocked position to the locked position as the tail247 of the firing member is advanced distally along the lockout lever.(FIG. 33). With the lockout lever 582 in the locked position, aproximal, locking end 586 of the lockout lever interferes with a lockrecess on the drive member 26, preventing further distal movement of thedrive member.

With continued reference to FIGS. 32A, 32B, and 33-34, if an unfiredreload is inserted into the reload support (FIG. 34), a tail 554extending proximally from the slider 550 engages a distal end of thelockout lever 582. As illustrated, the tail 554 acts on a lower surfaceof a distal portion of the lockout lever 582 distal the pivot point.This engagement of the slider tail 554 with the distal end of thelockout lever 582 pivots the proximal end of the lookout lever 582 awayfrom the drive member 26 even once the tail 247 of the firing member 240is no longer acting on the proximal portion of the lockout lever.Accordingly, the drive member 26 and firing member 240 can be distallyadvanced to fire the staples from the reload. Upon completion of afiring stroke, the slider 550 remains at a distal end of the reload.Thus if the jaw assembly is returned to the open configuration,withdrawing the firing member, the fired reload should be removed and anew unfired reload should be inserted to unlock the reload lockout.

With reference to FIGS. 35-37, an embodiment of articulation joint 300to couple the jaw assembly 30 to the distal end of the elongate shaft 20is illustrated. In the illustrated embodiment, the articulation joint300 comprises an articulation rod 310 pivotably coupled to the jawassembly laterally offset from a central longitudinal axis of the shaftassembly. A pivot joint is positioned along the central longitudinalaxis. The articulation joint 300 further comprises a support link 320pivotably coupled to the jaw assembly laterally offset from the centrallongitudinal axis of the shaft and opposite the articulation rod. Thedrive beam 26 extends longitudinally along the central longitudinal axisbetween the articulation rod 310 and the support link 320. At least asegment of the drive beam 26 extending through the articulation joint300 is flexible. In some embodiments, the drive beam 26 can be coupledto a flexible segment comprising a stack of shim material, which isflexible while maintaining desired force transmission capabilities for astaple firing operation. The articulation joint can further comprise oneor more drive member bearings 330 positioned laterally outwardly of thedrive beam 26. In some embodiments, the drive bearings 330 can comprisea flexible plastic material (FIG. 36). In other embodiments, the drivebearings 330′ can be comprised of a metal shim material (FIG. 37).Advantageously, the metal shim drive bearing 330′ can be keyed into theshaft to provide support to the flexible segment of the drive member.Moreover, the metal shim bearings can have a relatively low profileconfiguration. The metal shim bearings can include a low frictioncoating such as a TEFLON coating to reduce friction during a firing.

With reference to FIGS. 38A-38B, articulation of the articulation jointto position the jaw assembly in a first articulation position and asecond articulation position are illustrated. The articulation rod 310can be translated proximally (FIG. 38A) or distally (FIG. 38B) relativeto the shaft. The lateral offset positioning of the articulation rod 310articulates the jaw assembly relative to the shaft responsive totranslation of the articulation rod. The support link 320 opposite thearticulation rod 310 is passive, but can guide articulation motion ofthe jaw assembly and can advantageously assist in maintaining theflexible portion of the drive beam 26 towards the center of the shaft atthe articulation joint, preventing the flexible portion of the drivebeam 26 from buckling at the articulated bend at the articulation joint.In other embodiments, the articulation joint can include twoarticulation rods instead of an articulation rod and support link. Inembodiments with two articulation rods, an articulation latch mechanismcan be positioned in the shaft to prevent undesired articulation once astaple firing operation has commenced. For example, a latch or brakemechanism can retain the articulation rods from further movement oncethe drive beam 26 is translated distally.

With reference to FIGS. 39-40, another embodiment of articulation joint300′ to couple the jaw assembly 30 to the distal end of the elongateshaft 20 is illustrated. The articulation joint 300′ comprises anarticulation latch mechanism 340 positioned in the elongate shaft. Inthe illustrated embodiment, the articulation joint 300′ comprises anarticulation rod 310′ pivotably coupled to the jaw assembly laterallyoffset from a central longitudinal axis of the shaft assembly. A pivotjoint is positioned along the central longitudinal axis. Thearticulation joint 300′ further comprises a support link 320′ pivotablycoupled to the jaw assembly laterally offset from the centrallongitudinal axis of the shaft and opposite the articulation rod. Thedrive beam 26′ extends longitudinally along the central longitudinalaxis between the articulation rod 310′ and the support link 320′. Atleast a segment of the drive beam 26′ extending through the articulationjoint 300′ is flexible. In some embodiments, the drive beam 26′ can becoupled to a flexible segment comprising a stack of shim material, whichis flexible while maintaining desired force transmission capabilitiesfor a staple firing operation. The articulation joint can furthercomprise one or more drive member bearings 330 positioned laterallyoutwardly of the drive beam 26′. In some embodiments, the drive bearings330 can comprise a flexible plastic material (FIG. 36). In otherembodiments, the drive bearings 330′ can be comprised of a metal shimmaterial (FIG. 37). Advantageously, the metal shim drive bearing 330′can be keyed into the shaft to provide support to the flexible segmentof the drive member. Moreover, the metal shim bearings can have arelatively low profile configuration. The metal shim bearings caninclude a low friction coating such as a TEFLON coating to reducefriction during a firing.

With reference to FIGS. 41-42, articulation of the articulation joint toposition the jaw assembly in a first articulation position and a secondarticulation position are illustrated. The articulation rod 310′ can betranslated proximally (FIG. 41) or distally (FIG. 42) relative to theshaft. The lateral offset positioning of the articulation rod 310′articulates the jaw assembly relative to the shaft responsive totranslation of the articulation rod. The support link 320′ opposite thearticulation rod 310′ is passive, but can guide articulation motion ofthe jaw assembly and can advantageously assist in maintaining theflexible portion of the drive beam 26′ towards the center of the shaftat the articulation joint, preventing the flexible portion of the drivebeam 26′ from buckling at the articulated bend at the articulationjoint. In other embodiments, the articulation joint can include twoarticulation rods instead of an articulation rod and support link.

With reference to FIGS. 39-43, the articulation latch mechanism 340 orbrake mechanism of the articulation joint 300′ can retain thearticulation rod and support link from further movement once the drivebeam 26′ is translated distally. In the illustrated embodiment, thelatch mechanism 340 is positioned within the elongate shaft between theproximal end and the distal end thereof. The articulation latchingmechanism 340 has an unlatched configuration in which the articulationrod and the support link are slidable within the elongate shaft. Thus,with the articulation latching mechanism in the unlatched configuration,a user can articulate the jaw assembly relative to the elongate shaft byoperation of an articulation control on the handle assembly. Thearticulation latching mechanism 340 further comprises a latchedconfiguration (FIG. 43), wherein the articulation latching mechanismengages the articulation rod and the support link to preventlongitudinal sliding of the articulation link and the support linkrelative to the elongate shaft. Thus, in the latched configuration, thejaw assembly is retained in an articulated position and the user isprevented from articulating the jaw assembly relative to the elongateshaft.

With continued reference to FIGS. 39-43, in the illustrated embodiment,the articulation latching mechanism 340 comprises a first latch surface,such as a first plurality of teeth 342 formed on the articulation rod310′. As illustrated, the first plurality of teeth 342 is positionedwithin the elongate shaft between the proximal end and the distal end ofthe articulation rod 310′. The articulation latching mechanism 340 canfurther comprise a second latch surface, such as a second plurality ofteeth 344 formed on the support link 320′. As illustrated, in theembodiment of elongate shaft assembly having a latching articulationmechanism, the support link 320′ can extend proximally within the shaftthrough the articulation latching mechanism 340. In the illustratedembodiment, the second plurality of teeth 344 is positioned between theproximal end of the support link and the distal end of the support linkadjacent the proximal end of the support link 320′.

In the illustrated embodiment, the articulation latching mechanism 340further comprises a first shoe 346 having a mating surface such as afirst pawl surface 348 formed thereon. The first pawl surface 348 issized and configured to be engageable with the first plurality of teeth342. The first shoe 346 can have a deployment surface opposite themating surface, the deployment surface is in sliding engagement with thedrive beam 26′. The articulation mechanism 340 can further comprise asecond shoe 350 having a mating surface such as a second pawl surface352 formed thereon. The second pawl surface 352 is sized and configuredto be engageable with the second plurality of teeth 344. The second shoe350 can have a deployment surface opposite the mating surface, thedeployment surface in sliding engagement with the drive beam 26′. Thearticulation latching mechanism 340 can further comprise a latchingprofile formed on the drive beam 26′ between the proximal end and thedistal end thereof and positioned within the elongate shaft. In theillustrated embodiment, the drive beam 26′ comprises a recess segment360 formed therein, a tapered or ramped segment 362 proximal the recesssegment, and a latching segment 364 proximal the ramped segment. Therecess segment 360 has a first width in a direction generallyperpendicular to the longitudinal axis of the elongate shaft, and thelatching segment 364 has a second width greater than the first width.The articulation latching mechanism can further comprise a biasingmember such as a spring clip 370 coupled to the first and second shoesand biasing the shoes 346, 350 out of engagement with the first andsecond pluralities of teeth 342, 344. The spring clip can also maintainengagement of the deployment surfaces of the shoes 346, 350 with thelatching profile of the drive beam 26′.

With continued reference to FIGS. 39-43, in operation, the articulationlatching mechanism 340 can initially be positioned in the unlatchedconfiguration (FIGS. 39-42) such that the jaw assembly can bearticulated to a desired orientation relative to the elongate shaft. Inthis initial positioning, the drive beam 26′ is in a proximal positionrelative to the elongate shaft, corresponding to an open or partiallyclosed configuration of the jaw assembly. In the unlatchedconfiguration, the first and second shoes 346, 350 are positionedadjacent the recess segment 360 of the drive beam 26′ in a radiallyinward position. Once a desired articulated position of the jaw assemblyhas been selected, a user can proceed to close and fire the jawassembly, resulting in distal actuation of the drive beam 26′ relativeto the elongate shaft. This distal movement of the drive beam 26′advances the ramped and latching segments 362, 364 over the deploymentsurfaces of the first and second shoes 346, 350, advancing the shoesradially outwardly. (FIG. 43). With the first and second shoes 346, 350in the radially outward configuration, the first pawl surface 348engages the first plurality of teeth 342, and the second pawl surface348 engages the second plurality of teeth 342 to configure thearticulation latch mechanism in the latched configuration. Opening thejaw assembly after a firing sequence will reverse the sequence andreturn the articulation latch to the unlatched configuration. Thus,desirably, actuation of the drive member 26′ to close and fire the jawassembly automatically latches an articulated position of the jawassembly. Advantageously, this latching can reduce or prevent anytendency of the jaw to ‘wag’ relative to the elongate shaft as the drivebeam is advanced around and retracted through the articulation bend.While the illustrated embodiment of actuation latching mechanismincludes meshing arrays of teeth on the shoes and actuation rod andsupport link that define a plurality of discreet latched positions, itis contemplated that in other embodiments, the shoes, actuation rod, andsupport link can be configured to frictionally engage to define acontinuous array of latched articulation positions. Moreover, while theillustrated embodiment includes two shoes each engageable with acorresponding plurality of teeth, in other embodiments, a single shoecan be advanceable to engage a single plurality of teeth on thearticulation rod or support link.

With reference to FIGS. 44 and 45A-45D, a coupler 46 at the distal endof the handle assembly 40 can be coupled to the proximal end of theshaft assembly 20. The coupler 46 can include a bayonet connection witha lock-in. In the illustrated embodiment, the reload shaft 20 to handle40 connection comprises a bayonet style connection, in which a useraxially aligns and inserts the reload shaft 20 into the handle 40 androtates the reload shaft 20 approximately 90 degrees to connect. Thisbayonet connection operatively couples two mechanical functions of thereload shaft 20 to corresponding actuators of the handle 40. When thebayonet connection is fully coupled, an articulation member within theshaft 20 is coupled to an articulation adapter of the handle and a drivemember within the shaft 20 is coupled to the actuation adapter.Furthermore, the handle 40 and shaft 20 can be configured with a latchmechanism at the coupler 46 to prevent a user from removing the shaft 20once the actuation adapter and drive member has been activated.Moreover, the connection at the coupler 46 can include a reloadidentifying mechanism such that the control system of the handle candetect if a reload shaft is connected, and if so what the attached jawlength of the reload is. It is contemplated that the handle can be usedwith reload shafts 20 including different length jaw assemblies. In someembodiments the same handle 40 can be used with either 45 mm or 60 mmlength jaw assemblies.

In FIG. 45A, the shaft 20 is positioned in alignment with the coupler 46on the handle, and a release knob of the coupler 46 is withdrawn toexpose a bayonet channel 152 of the coupler 46 on a rotation insert ofthe coupler 46. The shaft 20 can include a retention post 22 or bosspositionable within the bayonet channel 152. In the illustratedembodiment, the shaft includes two bosses positioned 180 degrees aparton the outer surface thereof and the coupler 46 includes a correspondingtwo bayonet channels 152. It is contemplated that in other embodiments,other numbers and configurations of bosses and bayonet channels can beused to provide a desired connection strength and ease of alignment.

With reference to FIG. 45B, the retention post 22 of the shaft ispositioned within the bayonet channel 152. With reference to FIG. 45C,the reload shaft 20 has been rotated 90 degrees relative to the handlesuch that the retention post 22 of the shaft has reached a connected endof the bayonet channel 152. With reference to FIG. 45D, the release knobof the coupler is released to allow a retention recess 154 on therelease knob to retain the retention post 22 of the reload shaft 20.

With reference to FIGS. 46 and 47, the shaft assembly can include atubular shaft with the drive member or drive beam 26 and articulationmember 206 extending therethrough from the proximal end to the distalend. The drive member can extend generally centrally through the shaftassembly while the articulation member is laterally offset. The proximalend of the tubular shaft can include a coupling collar 410 for couplingto the coupler 46 at the distal end of the handle. In the illustratedembodiment, the shaft assembly can include a proximal shaft ‘lock out’mechanism. The lockout mechanism comprises a locking ring positionedwithin a shaft coupler at the proximal end of the elongate shaft and atleast one lockout member radially outwardly advanceable through thecoupling collar 410. The lockout member can be biased radiallyoutwardly, but held in a radially inward position by the locking ring inan initial position. When the proximal end of the shaft is coupled to ahandle assembly in a rotation sequence corresponding to a bayonetconnection, the locking ring is engaged with a mating surface in thehandle assembly and rotates relative to the elongate shaft. Thisrotation of the locking ring releases the lockout member. Upon removalof the shaft from the handle assembly, the lockout member radiallyexpands. In this expanded position, the lockout member interferes withrecoupling the elongate shaft to the handle assembly. Thus, this lockoutmechanism can serve to limit inadvertent reuse of an elongate shaftassembly.

With reference to FIGS. 48A and 48B, engagement of the bayonet couplingbetween the shaft assembly and the handle is illustrated. The coupler ofthe handle can comprise a rotation sleeve for coupling to the couplingcollar 410 in which an actuation adapter 124, an articulation adapter204, and an identification sleeve 208 are positioned. During a bayonetcoupling, the drive member of the shaft engages 26 with the actuationadapter 124, the articulation member 206 of the shaft engages with thearticulation adapter 204, and a shaft identifier engages with theidentification sleeve 208. FIGS. 49A and 49B illustrate the respectiveengagements with the shaft in a coupled configuration.

With reference to FIGS. 50 and 51, instead of or in addition to thelockout mechanism described with reference to FIGS. 46 and 47, certainembodiments of elongate shaft can include a lock-in or retentionmechanism that operates upon initial distal advancement of the actuationadapter 124. As illustrated, a locking member 24 is pivotably coupled toa proximal end of the shaft 20. The locking member 24 can include aramped or tapered lock surface at a proximal edge thereof. Asillustrated in FIG. 50, the shaft 20 is in a coupled, but unlockedconfiguration with respect to the coupler 46. In the coupled, unlockedconfiguration, the shaft 20 can be removed from the coupler 46 throughthe bayonet connection by a reverse of the sequence of operations ofFIGS. 45A-45D. Once the actuation adapter 124 is advancing to operatethe stapler, the actuation adapter 124 interacts with the ramped surfaceof the locking member 24 to advance the locking member radially outwardinto a locked position. In the locked position (FIG. 51), the lockingmember 24 engages a locking ledge on the coupler 46 to lock in theshaft. With the shaft 20 locked in with respect to the handle 40, theshaft 20 cannot be removed from the handle 40 until the actuationadapter 124 has been returned to a fully proximally retracted position(typically corresponding to a return to a jaws open configurationfollowing a full closure and stapling cycle of the jaw assembly).

Thus, the “lock In” feature prevents a user from removing the shaft fromthe handle once the drive member 26 has been driven forward. Once thelocking member 24 is situated in the slot or ledge of a rotation insertof the coupler 46, a release knob of the coupler 46 is restricted frombeing pulled back. This locking action on the coupler prevents the userfrom rotating the shaft 20 out of the bayonet connection of the coupler46.

With reference to FIG. 52, a proximal end of the shaft assemblycomprises a shaft coupler or coupling collar 410 positioned on theproximal end of the tubular shaft. Thus, the stapling system describedherein can easily be adapted for use with shaft assemblies havingvarious diameters. In some embodiments, an inner diameter the shaftcoupler can be readily resized to accommodate various tubular shaftswithout requiring different handle assemblies to accommodate shaftassemblies of various diameters.

Although this application discloses certain preferred embodiments andexamples, it will be understood by those skilled in the art that thepresent inventions extend beyond the specifically disclosed embodimentsto other alternative embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Further, the variousfeatures of these inventions can be used alone, or in combination withother features of these inventions other than as expressly describedabove. Thus, it is intended that the scope of the present inventionsherein disclosed should not be limited by the particular disclosedembodiments described above, but should be determined only by a fairreading of the claims.

What is claimed is:
 1. A reload assembly for a surgical stapling system,the reload assembly comprising: an elongate shaft having a proximal endand a distal end and defining a longitudinal axis extending between theproximal end and the distal end; a jaw assembly positioned at the distalend of the elongate shaft, the jaw assembly comprising: a first jawcomprising a reload support configured to receive a staple reload; and asecond jaw pivotably coupled to the first jaw, the second jaw comprisingan anvil surface; an actuation beam longitudinally slidable within theelongate shaft, the actuation beam having a proximal end and a distalend, the distal end of the actuation beam coupled to the jaw assembly;and a shaft coupler at the proximal end of the elongate shaft, the shaftcoupler comprising a locking member positioned therein, the lockingmember radially outwardly advanceable by distal actuation of theproximal end of the actuation beam.
 2. The reload assembly of claim 1wherein the shaft coupler has an unlocked configuration with the lockingmember in a radially inward position, the shaft removably positionablein a coupler of a handle assembly in the unlocked configuration.
 3. Thereload assembly of claim 1, wherein the shaft coupler has a lockedconfiguration with the locking member radially outwardly advanced. 4.The reload assembly of claim 1, wherein the locking member is pivotablycoupled to the elongate shaft and pivotable from an unlocked position toa locked position.
 5. The reload assembly of claim 2, wherein thelocking member comprises a lever having a proximal end, thelocking1member comprising a tapered lock surface at the proximal endthat is radially outwardly advanceable by distal actuation of theactuation beam.
 6. A reload assembly for a surgical stapling system, thereload assembly comprising: an elongate shaft having a proximal end anda distal end and defining a longitudinal axis extending between theproximal end and the distal end; a jaw assembly positioned at the distalend of the elongate shaft, the jaw assembly comprising: a first jawcomprising a reload support configured to receive a staple reload; and asecond jaw pivotably coupled to the first jaw, the second jaw comprisingan anvil surface; an actuation beam longitudinally slidable within theelongate shaft, the actuation beam having a proximal end and a distalend, the distal end of the actuation beam coupled to the jaw assembly;and a shaft coupler at the proximal end of the elongate shaft, the shaftcoupler configured to removably couple to a handle assembly, the shaftcoupler comprising a lockout mechanism positioned therein, the lockoutmechanism comprising a locking ring rotatable about the longitudinalaxis; and a lockout member radially outwardly advanceable by rotation ofthe locking ring.
 7. The reload assembly of claim 6, wherein the lockoutmember is extendable through a port in the shaft coupler to a lockedposition radially outwardly of the shaft coupler.
 8. The reload assemblyof claim 7, wherein with the lockout member in the locked position, thelockout mechanism interferes with coupling the shaft coupler to a handlecoupler.
 9. A reload assembly for a surgical stapling system, the reloadassembly comprising: an elongate shaft having a proximal end and adistal end and defining a longitudinal axis extending between theproximal end and the distal end; a jaw assembly articulably coupled tothe elongate shaft at the distal end of the elongate shaft, the jawassembly comprising: a first jaw comprising a reload support configuredto receive a staple reload; a second jaw pivotably coupled to the firstjaw, the second jaw comprising an anvil surface; an actuation beamlongitudinally slidable within the elongate shaft to actuate the jawassembly, the actuation beam having a proximal end and a distal end; anarticulation link longitudinally slidable within the elongate shaft toarticulate the jaw assembly relative to the elongate shaft, thearticulation link having a proximal end positioned adjacent the proximalend of the elongate shaft and a distal end pivotably coupled to the jawassembly; a support link longitudinally slidable within the elongateshaft, the support link having a proximal end extending longitudinallyto a distal end pivotably coupled to the jaw assembly; and anarticulation latching mechanism positioned within the elongate shaftbetween the proximal end and the distal end, the articulation latchingmechanism having an unlatched configuration in which the articulationlink and the support link are slidable within the elongate shaft and alatched configuration wherein the articulation latching mechanismengages the articulation link and the support link to preventlongitudinal sliding of the articulation link and the support link. 10.The reload assembly of claim 9, wherein the articulation link comprisesa first plurality of teeth formed thereon between the proximal end andthe distal end of the articulation link, the support link comprises asecond plurality of teeth formed thereon between the proximal end andthe distal end of the support link and the articulation latchingmechanism comprises: a first shoe having a first pawl surface formedthereon, the first shoe engageable with the first plurality of teeth; asecond shoe having a second pawl surface formed thereon, the second shoeengageable with the second plurality of teeth; and a biasing membercoupled to the first shoe and the second shoe and biasing the first shoeand the second shoe out of engagement with the first plurality of teethand the second plurality of teeth.
 11. The reload assembly of claim 10,wherein the actuation beam comprises a recess segment formed between theproximal end and the distal end of the actuation beam, a ramped segmentproximal the recess segment, and a latching segment proximal the rampedsegment.
 12. The reload assembly of claim 11, wherein with the actuationbeam in a proximal position, the first shoe and the second shoe aredisposed radially outwardly of the recess segment and the articulationlatching mechanism is in the unlatched configuration.
 13. The reloadassembly of claim 12, wherein upon distal movement of the actuationbeam, the ramped segment and latching segment engage the first shoe andthe second shoe are advanced radially outwardly into engagement with thefirst and second plurality of teeth to position the articulationlatching mechanism in the latched configuration.
 14. The reload assemblyof claim 10, wherein the biasing member comprises a spring clip biasingthe first shoe and the second shoe radially inwardly.
 15. The reloadassembly of claim 10, wherein the first pawl surface comprises a firstplurality of teeth formed in the first shoe and extending radiallyoutwardly from the first shoe.
 16. The reload assembly of claim 15,wherein the second pawl surface comprises a second plurality of teethformed in the second shoe and extending radially outwardly from thesecond shoe.
 17. The reload assembly of claim 10, wherein the proximalend of the support link is disposed between the proximal end and thedistal end of the elongate shaft.